1. Field of the Invention
This invention relates to encased instantly cookable pasta including various types of pasta and Chinese and Japanese noodles, and method and apparatus for producing such instantly cookable pasta.
2. Background of the Invention
Generally, a variety of pasta, Chinese noodle and Japanese noodle are available in an uncooked, semi-cooked or dried form. When serving noodle as a cold dish, it is usually boiled in water for a predetermined time period, scooped up into a wire basket and then washed with cold water in a bowl or the like.
Upon boiling wheat or buckwheat noodle or vermicelli or Chinese noodle, exudation of starch components is likely to occur, forming slimy covering on the surfaces of noodle threads. In order to remove the slimy covering, which impairs not only the palatable touch of the noodle but also the flavor of the soup, the boiled noodle is usually washed in cold or hot water provided separately from the first-mentioned hot water in which the noodle was boiled. Immediately before being served, the noodle is warmed again in fresh hot water.
However, a difficulty is often encountered in that the noodle threads are apt to break off or flow out when taking them out of boiling water or when washing them with hot or cold water. Besides, each time when washing noodle in water, a wire basket or other container has to be provided to collect the washed noodle, taking a great deal of time and effort. While washing in water, the individual noodle threads have to be separated from each other with meticulous skill to remove the slimy covering to a sufficient degree without breakage of the noodle threads, since the slimy covering would otherwise impair the flavor of the soup as mentioned hereinbefore.
In case of instantly cookable noodle which can restore cooked edible state upon boiling in hot water for 3 to 5 minutes, the noodle is usually formed into a structure which is porous, reduced in thickness or hollowed to shorten the time of restoration at the sacrifice of cord strength as compared with dry noodle or vermicelli. Therefore, if the instant-cooking noodle is thrown into hot boiling water, it is swirled in the boiling water and caused to lose the "aldente" consistency to such a degree as would impair its taste. Especially, hollowed Bucatini type instantly cookable spaghetti is susceptible to the loss of "aldente" consistency when swirled in boiling hot water, resulting in problems such as degraded taste of the spaghetti itself, irregularities in the degree of cooking or ready breakage of the individual cords while being eaten.
Aside from the problems which arise when boiling the pasta in preparation of a meal, the instantly cookable pasta has the following problems.
As known, for example, from Japanese Patent Publication No. 49-15780 and its corresponding U.S. Pat. No. 3,537,862 (hereinafter referred to simply as "the other prior art" for brevity), it has been the usual practice to produce instant-cooking pasta by mixing (kneading) strong wheat flour or the like with 20-40 wt % of water, forming the resulting mixture into raw pasta cords or strips of a predetermined shape with the use of a suitable shaping means such as shaping rollers or extruder, cooking the shaped pasta in steam, and drying the cooked pasta.
In the just-mentioned other prior art method in which uncooked raw pasta cords from a pasta shaping means are subjected to steam-cooking and drying treatments, it is necessary to steam the raw pasta cords to a sufficient degree to obtain an instantly cookable pasta with a relatively shortened time of restoration, by increasing the rate of .alpha.-conversion in the steam-cooking treatment. However, a difficulty arises in that the individual cords of the pasta tend to stick to each other as a result of exudation of starch components induced by water deposition on the pasta cords under the steam-cooking treatment, making it difficult to turn the pasta into edible state uniformly on preparation of a meal due to bondage, cohesion and deformation of the individual pasta cords.
In this connection, as described in Japanese Patent Publication 56-39614 and corresponding U.S. Pat. No. 4,368,210, the applicants proposed a method of producing instantly cookable pasta by accelerating a-conversion of starch components by subjecting a kneaded mixture of wheat flour and water to preliminary steam-cooking, shaping the resulting mixture into a predetermined form, for example, into a strip- or cord-like form, and, if necessary, depositing water or the like on the surface of the shaped pasta strip or cord, followed by a steam-cooking treatment and drying. This method can suppress exudation of starch at the time of the steam-cooking treatment to prevent cohesion of individual pasta strips or cords, but still has a difficulty in thermally converting all of the gluten content in the kneaded mixture into a desirable gluten structure at the time of the preliminary steaming, resulting in pasta strips or cords which are hardened to an excessive degree and lack elasticity in terms of tasteful touch to the mouth, the pasta strips or cords being increased only in viscosity to give a sticky touch to the teeth instead of a palatable feeling. Besides, the high viscosity after the preliminary steam-cooking makes it difficult to form the pasta cords or strips by the use of shaping rolls.
Further, Japanese Laid-Open Patent Application 63-248366 discloses a method of shaping a starting mixture into linear pasta cords by extrusion without preliminary steam-cooking, and loosely separating the individual pasta cords by depositing an emulsion on the surfaces thereof after a primary steam-cooking treatment, followed by secondary steam-cooking and drying treatments. In this case, however, the time for the primary and secondary steam-cooking treatments has to be prolonged as a whole for cooking the elongated linear pasta cords or strips of a greater thickness or breadth free of waves or crimps like spaghetti. Since the individual pasta cords (strips) have a greater area of contact, they tend to stick to each other during the cooking treatments in the absence of effective means for preventing bondage of the pasta cords or strips, failing to improve the palatable feeling in terms of smoothness and resiliency.